Mike- Eagle is the 2009 & later 5.7. Different heads and VVT are the main differences vs the early 5.7s
The bolt patterns are all the same but the early 5.7L heads (03-08) are there own entity and have a narrow but tall port and the eagle,6.1L,6.2L,6.4L heads all have the same port window and are wide and short.
Also if you plan on using the MSD ignition controller they only work with the early reluctor wheels unless MSD has upgraded.